Tagged: slipcast

To the darkroom!……

(title should be read in the voice of Batman’s Adam West)

Ok, the time is upon us – time to make this ceramic ball into a camera!

I’m using Rockland Liquid Light, not used this brand before, so we’ll see how it goes. I have some jugs as well..

Photo 29-04-2013 15 37 57 (1)

The darkroom kit

The liquid light is a solid(ish) gel at room temperature, it has to be heated up to melt it into a pourable liquid. I let the bottle stand in a jug of hot water for a few minutes until it had liquidised. I also placed the ceramic ball on top of a jug with hot water, so the steam/heat from the water would warm the bottom of the ball, making sure the liquid light didn’t start to harden as soon as it was poured into the ball.

Photo 07-05-2013 16 59 54

hot water baths

Time to turn out the lights…….

The liquid light behaves in the same way as photographic paper, it’s orthochromatic, which means it’s not sensitive to red light, therefore can be handled in normal darkroom conditions (over exposure to red light will eventually fog the emulsion, as it does with photographic paper, but that can take a while, I’ll be done before that happens – hopefully)


Darkroom adventures

The emulsion is poured into the ball using a small funnel [1] [2] after being swished around inside the ball for a few minutes, to coat as much of the inside as possible, the liquid light is poured back into the bottle [3] The ball is kept moving for a few more minutes to prevent the remaining liquid light from pooling on the bottom. The pinhole plate I made earlier is stuck over the hole in the ball using extra trape making the ball now light tight [4]

Photo 07-05-2013 17 14 50

The pinhole camera ready to go

With the pinhole plate stuck over the hole it’s safe to turn the lights back on, and there we have it – the first slip cast pinhole camera (for it is no longer a ceramic ball – it has been blessed with light capturing magic inside, making it now officially a camera).

I still have no idea if this will work, the liquid light might not stick to the clay walls (although it should as the clay is still porous), I have no idea how thick the emulsion is – from this point onwards it’s all speculations and fingers crossing…….

Oh – I also made a few more balls

Photo 08-05-2013 15 34 55

more balls

I also realised that I’d need something to hold them still, they kept rolling around the desk top, precariously close to falling off, so I quickly made some bases for them to stand in from a large poster tube – these will also be used as a base to hold the balls in when I take the photographs.

I noticed that two together looked like the eyes from Zig & Zag or Berk from Trapdoor

Photo 08-05-2013 15 35 13 copy

Showing my age now :/

Anyway, where was I? Oh yes, the camera..

Well it’s ready to go, just need to wait for a nice day (could be a while) to go and find something cool to photograph, so watch this space!……

Slip and pinholes…..

Photo 19-04-2013 10 32 00Been a bit busy at work recently, so not had much time to crack on with this, but whist the ball is in the kiln being fired I made up some new slip to cast some more balls. Slip is basically liquid clay, clay particles suspended in water. I could buy it from ceramic suppliers, but I thought I’d mix up my own (keep the home made feel to everything)

I started with some clay that had been soaking in water for a while, making it all squishy (a technical term 😉 ) then just got stuck in with my hands squidging and squeezing (again, all technical terms) it through my fingers to mix it into a thickish slurry – you can use a drill with a mixer attachment for this as well, and I probably will when I make up a larger batch – you’re looking for it to be faily thick but not too thick, something like the consistency of cream. It then needs to be sieved through a fine sieve to remove any big lumps and make the slip smooth. A deflocculant is added to keep the clay particles suspended in the water, in other words, it stops all the clay settling to the bottom of the container. I used some sodium silicate for this, dissolved in a little bit of warm water. The slip was then poured into the storage container.


Mixing up more slip

The next day the ceramic ball had been fired, it looked good, felt a nice size to hold and appeared to be light tight – I was worried that the walls might be too thin that a bit of light would sneak through, but it looks fine. It’s still a bit rough looking – I’ll have to work on that on the next ones.

fired ball 2 up

first fired ball

Ok – time to make the pinhole for it. For any photographers following, you’ll all probably be familiar with how to make a pinhole, for those who don’t, here’s how I make mine…

First I worked out what’s the best size to make the pinhole- this depends on the focal length of the camera (the distance from the pinhole to where the film plane is) – in this case the distance from the hole in the ball where the pinhole plate will be and the back of the ball – it worked out at around 11cm. There’s plenty of websites out there that will calculate optimum pinhole sizes based on focal length, and vice versa, I tend to use MrPinhole, Mr Pinhole told me the best size for my pinhole is 0.45mm.

I gathered the bits I needed: a bit of thin tin, a 0.4mm drill bit and Archimedean drill, a bit of blue tack, a ballpoint pen, fine wet and dry paper.

Start off by placing the tin onto the bluetack, and press the ballpoint pen tip into the tin to make a small indentation (I forgot to photograph this bit), turn the tin over and sand down the bump made by the pen tip – this makes the tin even thinner for when you make the pinhole. Turn the tin back over and drill the pinhole where you made the dint, use the bluetack underneath to stop from drilling holes into your table top (if you do accidentally drill into the table top, drill loads more holes and blame it on woodworm). Flip the tin over again and sand down the back of the hole to make it smooth. This also enlarges the hole slightly, so my 0.4mm hole should go up to around 0.45mm – what I’m looking for.

As the surface of the ball is round I curved the tin pinhole plate slightly so it would sit better on the ball. I attached the pinhole plate to some heavy duty tape (with a small square cut out to allow access to the pinhole) and coloured the exposed tin black with a Sharpie, just to cut down on any stray light bouncing around the inside of the camera. The tape will allow me to stick the pinhole to the camera.


making of the pinhole

So the pinhole is now ready to attach to the ceramic camera – I just need to make it light sensitive, that’s a job for next week ……

Quick update….

Well, I checked out the state of my latest cast on friday – this time is was fine – except for a small hole in the side, which I filled with some extra slip (hence the messy edge in the photo)


new cast – looking good

The walls are proabably a little thin, so I’ll have to leave the slip for a bit longer next time to thicken the walls. It does feel really nice to hold though.

It is a bit rough – I might do a recast of the small ball again to make them smoother – take my time with it – as I do like the asthetics of the smaller size  (I’m still going to do the larger size ones though – well, it’ll be rude not to)

All i need to do now for this one is to bisque fire it to 1000˚c (sometimes known as ‘buiscuit fire’ as well) this will solidify the clay, making it stronger – but still porous, which will allow the liquid light to stick to the surface when its poured in.

This process is taking a looooooong time (I could speed it up by press moulding the balls, but I like the idea that everything is liquid  –  liquid clay, liquid light, liquid developing chemicals) so I’m sorry there’s large waits between updates.

I’m going to make several casts of the ball I think – that will speed things up for when it comes to making the cameras.

The first casting, and a lesson learned…..

Photo 02-04-2013 12 13 10Just over a week ago the mould seemed to be dry enough to pour a slip cast. The only slip I had on hand was a white grogged clay. Grogged means the slip has small bits of crushed fired clay mixed in, giving it a grainy texture – it helps to prevent shrinkage when drying and firing, and cuts down on the chance of air pockets forming in the clay. This slip will be fine for the test, it’ll dry pale enough to be used as a base for the liquid light, it might be a bit rough due to the grog, but we’ll see….

The mould was sealed up around the join with some clay, just in case the slip leaked out the side, and a thick rubber strap held the two halves in place. The slip was poured in through the pour hole. As the plaster mould absorbes the moisture in the clay the clay sticks to the side of the mould, and the level of the slip goes down, so it needed constant topping up.

The longer you leave the slip in the mould the thicker the walls of clay will be, I left the slip in the mould for 5 minutes then poured out the remaining slip, leaving it to drain upsidedown over a jug. A few minutes later the mould was turned the right way up and the slip cast was left to dry out and the clay to stiffen up……


Top left – mould sealed up : Top right – slip poured in : Bottom left – left to settle : Bottom right – draining the slip out

A few days ago I was checking to see if it looked dry enought open, and it did, I got excited and wanted to see how it looked, so I opened it up ……


opened up mould

It looked ok – a bit rough, but then that was my fault fot not taking the extra time to smooth the release agent on the ball. The pour hole, where the slip was poured in looked good, big enough for the liquid light and chemicals later. There seemed to be a gap between the clay ball and the plaster mould – it had shrunk as expected, and I assumed that the clay ball was dry enough to remove…I tried to pull it out, it gave a little, I banged the base of the mould, nothing, so I took hold of the top of the ball and gently twisted…….

This is where the first lesson comes in – it appears I am too impatient – the clay had not dried out properly on the base, and as the ball came out the mould it left behind a big chunk of still wet clay, firmly attached to the bottom of the mould…..


Lesson no1 – I’m too imapient – let the clay dry properly next time!

Although a bit of a fail, this is not all that bad, it has given me an idea on how the balls will look with the front broken away (picture on the right above) showing the image on the inside, and it looks pretty cool, so that’s good.

(I know I’m impatient, and I think when I do these at full size, I’m going to have to make a load of moulds so I can make several cameras at once)

After a few swear words and giving myself a ticking off for being too imaptient, I poured up another slip cast, not crying over spilt cow juice and getting back on the horse and all that.

Photo 04-04-2013 11 00 41

take 2

Take 2 – Lets leave this one longer……